Soot removing apparatus for steam boilers and the like



28. 1956 N. o. B. ANDERSSON 2,760,222

SOOT REMOVING APPARATUS FOR STEAM BOILERS AND THE LIKE Filed Feb. 9, I953 5 Sheets-Sheet 1 28, 1956 N. o. B. ANDERSSON 2,760,222

SOOT REMOVING APPARATUS FOR STEAM BOILERS AND THE LIKE 3 Sheets-Sheet 2 Filed Feb. 9, 195a Aug. 28, 1956 N. o. B. ANDERSSON 2,760,222

SOOT REMOVING APPARATUS FOR STEAM BOILERS AND THE LIKE 5 Sheets-Sheet 3 Filed Fb. 9, 1 .953

United States Patent O" 500T REMOVING AliPARATUS FOR STEAM BOILERS AND TIE LIKE Nils Olof llirger Andersson, Danderyd, near Stockholm, Sweden, assignor to Aktiebolaget Superior, Stockholm, Sweden Application February g, 1953, fierial No. 335,903

Claims priority, application Sweden February 28, 1952 Claims. (Cl. -317) This invention relates to such soot removing apparatus for steam boiler plants and other heat-transmission systems, in which a jet tube, when in a position of rest, is retracted into the frame of the apparatus and, when operated, is during rotation moved forward to a front end position of reversal within the steam boiler plant or the like and then is moved back to the position of rest, a blowing medium being supplied during the forward and return movements through the jet tube by way of a main valve which preferably is controlled automatically by means of a servo-valve mechanically operated by the jet tube immediately after the initiation of its forward movement and immediately before the completion of its return movement, the jet tube being moved forward a great distance into the steam boiler plant or the like and the forward movement continuating after the main valve has opened.

A great number of soot removing apparatus of said type are generally used in one and the same steam boiler plant. All of the soot removing apparatus provided are simultaneously supplied with the blowing medium through corresponding branch conduits extending from a common main conduit. T o begin with the blowing medium cannot enter the jet tubes proper because each soot removing apparatus has its associated main valve held in closed position under the action of the closing pressure of the blowing medium, usually in co-operation with a closing spring. Not until the jet tube has been advanced some distance the main valve of the respective soot removing apparatus is opened by means of the servo-valve, this last-mentioned valve being opened in dependence upon the movement of the jet tube and thereby relieving the main valve from the pressure of the blowing medium acting in the closing direction, so that the main valve is opened. Each soot removing apparatus may be provided with a separate electric driving motor which causes the jet tube to be moved longitudinally and rotated. The driving motors of the different soot removing apparatus are started by means of push button switches in a central equipment of supervision and control, Whereas two switches on each soot removing apparatus controlled in dependence upon the movement of the jet tube, together with relays are arranged to reverse the motor at the end of the forward movement and to stop the motor at the end of the return movement. However, the soot removing apparatus may be provided to be driven also by hand. Anyhow, the servo-valve is closed when the jet tube has performed its return movement, so that the opening force acting upon the main valve is balanced and then the main valve is closed.

Soot removing apparatus of the well-known automatic type set forth above are generally rather bulky and of a complicated construction, and the main object of the invention is to attain an improvement in these respects, still securing a reliable function.

A soot removing apparatus according to the invention comprises substantially the following novel features. The frame of the apparatus contains a carriage which is mov- 2,760,222 Patented. Aug. 28, 1956 able in parallel with the jet tube and is mounted on the jet tube, said tube being rotatable but non-displaceable relative to the carriage, viz. held against longitudinal movement in the carriage. Moreover, the frame of the apparatus contains an endless driving chain running in parallel with the jet tube, said chain being coupled with the carriage for moving the same longitudinally together with the jet tube and meshing with a chain wheel provided on a transversal axis in the carriage and serving to operate transmission means on the carriage for rotat ing the jet tube relative to the carriage. Thus, the invention is based upon the principle that both the longitudinal or axial movement of the jet tube and the rotation of the same is effected by one and the same endless driving chain extending in parallel with the jet tube.

Further object and features of the invention will appear from the following specification of a preferred embodiment of a soot removing apparatus according to the invention, by way of example schematically illustrated in the accompanying drawings in which:

Fig. 1 shows, on a reduced scale and in a side view, the total soot removing apparatus according to said preferred embodiment together with the adjacent section of the wall of a steam boiler;

Figs. 2a and 2b together show a vertical longitudinal cross-section through the soot removing apparatus according to said embodiment;

Fig. 3 shows a vertical transversal cross-section on the line III-III in Fig. 2b;

Fig. 4 shows a vertical transversal cross-section on the line IVIV in Fig. 2b;

Fig. 5 shows a horizontal cross-section on the line V-V in Fig. 2a;

In the enbodiment illustrated in Figs. l5, inclusively, the jet tube l is longitudinally movable on a stationary rear tube 2 and is provided with a blowing nozzle 3. The frame comprises a longitudinally extending beam 4 having a cross-section in the form of an inverted U, as well as the two terminal plates 5 and 6. The beam 4 is of a considerable length, such as about 3 metres, for example, and allows a corresponding travel of the jet tube, for instance about 2.5 metres. The terminal plate 5 carries a sleeve 7 adapted to be inserted into the wall W of the steam boiler for supporting the front end of the frame, as well as a sleeve 8 comprising a bearing for the jet tube 1 and also provided with a scrape-off or cleaning device, such as a ring-shaped brush 8' for cleaning the jet tube externally. Attached to the terminal plate 6 is a fastening member 9 for holding the valve body 10 containing the main valve 11 together with the guide and control piston 12, said main valve normally being held in closed position by the pressure P of the blowing medium which upon the opening motion of the servo-valve (to be described later) escapes through the relieving channel 13 and the servo-controlled relieving conduit 14 extending to the flue-gas space of the boiler or to collecting apparatus for condensation water. Such valve devices are well-known so that no detailed illustration of the same seems necessary.

At the ends the beam 4 supports the two end wheels 15 and 16 for the endless driving chain 17 extending in parallel with the jet tube, which two chain wheels 15, 16 are mounted on the horizontal transverse shafts 18 and 19, respectively. As illustrated especially in Figs. 2 and 3, the shaft 19 is rotated through the helical wheels 20, 21, the vertical shaft 22, the toothed Wheels 23, 24, the vertical shaft 25 and the Worm gear 26, 27 driven by an electric motor 28 provided on the beam 4 above the same. The shaft 22 has an upward extension and is pro vided with a hand Wheel 29. For operation by hand the toothed wheel 23 is disengaged by means of the lever 30 after the locking screw 31 has been disengaged.

The jet tube 1 has on its rear end portion (Fig. 2) a stiifening and bearing shell 32 on which the carriage 33 is mounted. Said carriage is made as a hollow body or housing and within this housing a helical wheel 34 is securely mounted on the jet tube 1 .and the shell 32. Said helical wheel meshes with another helical wheel 35 provided within the housing 33 and mounted on a horizontal transversal shaft 36 carrying a chain wheel 37 (Fig. 4) engaging the driving chain 17. The helical wheel 35 may be securely mounted on the shaft 36 in a well-known manner but in the embodiment illustrated the helical wheel 35 is according to a feature of the invention mounted on said shaft so as to allow a lost motion in the circumferential direction, such lost motion means comprising the arc-shaped recess 35' made in said helical wheel, and the key 36' cooperating with said recess and being securely inserted in the driving shaft 36.

The housing 33 supports on its external side a guide roller 38 (Fig. 2) for securing the engagement of the upper flight to the driving chain with the chain wheel 37. Moreover, the housing 33 has on its external side a coupling member 39 (Fig. 4) for connecting the housing with the lower flight of the driving chain. Thus, the driving chain will cause a longitudinal movement of the housing 33 together with the jet tube 1 by means of the coupling member 39, as well as a rotation of the jet tube by means of the chain wheel 37 and the associated transmission elements. The housing 33 carries guiding means for cooperation with the beam, such as a guiding roller 40 for engagement with a guiding rail 41 on the beam 4 and, if desired, a pair of supporting rollers 42 cooperating with the beam.

The servo-valve 45 already mentioned is, as shown in Fig. 4, a rotary valve, and the housing 46 of the same (see also Fig. 1) connected in the relieving conduit 14, 44, is provided on the beam 4. The valve stem 47 extends into the beam 4 and supports on its interior end a forkshaped operating member 48, the two arms of which extend downwards on opposite sides of the operating pin 49 attached to the housing 33. The spring 50 will resiliently hold the operating member 48 either in a rear position or in a front position, corresponding to closed and open positions, respectively, of the servo-valve,

The beam 4 supports also a switch box 51 (Figs. 1 and 5) together with a switch 52 which in Well-known manner actuates a relay for reversing the direction of rotation of the driving motor 28. Such relay arrangements are well-known in the art and do not constitute any part of the invention so that it has been considered superfluous to illustrate the same in the drawing. By means of a lever 54 and a sliding rod the spring 53 maintains the switch in closed position against the action of the spring 56. The arrangement is such that the housing 33 near the end of the forward movement actuates the lever 54 and relieves the sliding rod 55 from the pressure of the spring 53 so that the spring 56 can move switch to open position.

Moreover, the beam 4 supports a quite similar device for stopping the driving motor and thereby stopping the return movement of the jet tube. From this device only the switch box 57 is indicated in Fig. 1.

The apparatus thus described operates substantially in the following manner, the lost-motion means 35, 36' being disregarded to begin with. When the driving motor 28 is started from the central control equipment (not shown) the jet tube 1 starts immediately its forward and rotation movement. After a short travel the closed servo-valve 45 is moved to open position by means of the operating means 48, 49, whereby the pressure behind the piston 12 is relieved and the main valve 11 is opened for supplying the blowing medium. Now, the jet'tube 1 is, during rotation advanced into the space in the boiler to its maximum length. Immediately before position of re: versal the reversing switch 52 is actuated by the housing 33 and then the return movement begins. When the jet tube is retracted into its position of rest the stop switch in the box 57 is actuated.

It is to be understood that the invention allows a rather strong and clearly arranged structurecompare Fig. 1 comprising a comparatively low number of details, and also secures a reliable function. It should also be observed that the beam covers and houses the essential movable parts, such :as the driving chain together with associated "transmission means, the carriage together with associated transmission means, the operating means of the servo-valve and the switches, and so on.

In soot removing apparatus of the present main type, thus having a jet tube 1 performing combined longitudinal and rotary movements which are simultaneous with each other over at least the major part of the same, the construction is generally such that each aperture 3 of the nozzle 3 moves in exactly the same helical path both during forward and backward movement so that always the same spots on the tubes of the boiler are struck by the jets blown out. This is a disadvantage in part because the soot removing action is irregularly distributed and in part on account of the fact that the jets will subject the tubes of the boiler to corroding and mechanical attacks as they always hit the same points on the tubes.

It is also the object of the invention to eliminate said disadvantage, and according to a related feature of the invention the driving transmission of the jet tube is made to stop one of the two motions of the jet tubeviz. either the rotary movement or the longitudinal movementfor a short time interval at the position of reversal, whereby a phase displacement of the helical path during the backward movement relative to the helical path during the forward movement is obtained, so that the blowing mediurn emitted from the nozzle apertures will strike different points during the back movement than during the forward movement.

The lost-motion means 35, 36 already described serves said purpose and when said means are used as is the case in the embodiment illustrated, the manner of action will be as follows.

When the jet tube 1 is moved forward the key 36 is in engagement with one end of the recess 35 for transmitting the rotary movement of the driving shaft 56 to the helical wheel 35. In the position of reversal the driving chain 17 and thereby also the helical wheel 35 reverses its direction of rotation. In this position the longitudinal backward movement of the jet tube immediately starts but the rotation of the jet tube is delayed until the key 36' has moved through the recess 35 to the opposite end of the same, the rotary movement of the jet tube starting at said opposite end of the recess. Thus, the extent of the lost motion in the circumferential direction corresponds to the value of the stop interval provided in the rotary movement of the jet tube at the position of reversal.

On account of the lost-motion device according to the invention each aperture 3 of the nozzle will upon the reversal of the longitudinal movement of the jet tube travel a predetermined short distance in the backward direction without performing any rotary movement, and not until said predetermined longitudinal backward movement has been completed the rotary movement will start again. Thus, the helical path in which each aperture of the nozzle moves during the backward movement will be somewhat displaced in the longitudinal direction of the jet tube. Consequently, the jets of the blowing medium blown out through the apertures of the nozzle will cover.

a greater area in the boiler than would be the case if each aperture of the nozzle would move in exactly the Same helical path both during the forward movement and during the backward movement.

In the embodiment illustrated, the driving transmission of the jet tube is adapted to stop the rotary movement for a short time interval at the position of reversal during continued longitudinal movement (backwards), but it is also possible to make said transmission such that it stops the longitudinal movement of the jet tube for a short time interval at the position of reversal during continued rotary movement (backwards), so that the jet tube would rotate through a predetermined angle while remaining in the front end position. Also such a manner of action may be effected by means of lost motion means provided in a transmission wheel included in the driving train of the longitudinal movement of the jet tube, if the longitudinal and the rotary movement are effected by two corresponding driving trains operating in parallel.

However, the provision of the stop interval in the rotary movement as illustrated will allow an extremely simple construction especially in combination with a soot removing apparatus having a chain transmission according to the embodiment illustrated.

What I claim is:

l. A soot removing apparatus for heat transmission systems, comprising, in combination, a frame, a jet tube mounted for longitudinal and rotary movement in said frame, a valve for supplying a blowing medium through the jet tube, a carriage mounted in said frame for performing a longitudinal movement in parallel With the jet tube and simultaneously with the same, a driving endless chain extending in parallel with the jet tube one flight of said chain being coupled with the carriage for moving the same in the longitudinal direction, and transmission means on said carriage operatively interconnecting the other flight of the chain and the jet tube for imparting a rotary movement to the jet tube.

2. A soot removing apparatus for heat transmission systems, comprising, in combination, a frame, a jet tube mounted for longitudinal and rotary movement in said frame, a valve for supplying a blowing medium through the jet tube, a carriage mounted in said frame for performing a longitudinal movement in parallel with the jet tube and simultaneously with the same, an endless driving chain extending in parallel with the jet tube one flight of said chain being coupled with the carriage for moving the same in the longitudinal direction, a transverse shaft in said carriage, a chain wheel on the transverse shaft for engagement with the other flight of the driving chain and thereby driving said shaft, a transmission Wheel on said shaft, and a corresponding transmission wheel on the jet tube in mesh with the first-mentioned transmission Wheel for rotating the jet tube.

3. A soot removing apparatus for heat transmission systems, comprising, in combination, a frame, a jet tube mounted for longitudinal and rotary movement in said frame, a valve for supplying a blowing medium through the jet tube, a carriage mounted on the jet tube, said tube being rotative in relation to the carriage but held against longitudinal movement in the carriage, a driving endless chain extending in parallel with the jet tube one flight of said chain being coupled with the carriage for moving the same in the longitudinal direction, guiding means for holding the carriage against rotation and guiding the same in a longitudinal path in parallel with the jet tube, and transmission means on said carriage operatively interconnecting the other flight of the chain and the jet tube for imparting a rotary movement to the jet tube.

4. A soot removing apparatus for heat transmission systems, comprising, in combination, an oblong frame, a jet tube mounted for longitudinal and rotary movement in said frame, a valve for supplying a blowing medium through the jet tube, a hollow carriage body mounted on the jet tube, said tube being rotative in relation to the carriage body but held against longitudinal movement in the carriage body, a driving endless chain extending in parallel with the jet tube one flight of said chain being coupled with the carriage body for moving the same in the longitudinal direction, guiding means for holding the carriage body against rotation and guiding the same in a longitudinal path in parallel with the jet tube, a transverse shaft in said carriage body, a chain wheel on the transverse shaft outside the carriage body in engagement with the other flight of the driving chain and thereby driving said shaft, a transmission wheel on said shaft Within the carriage body, and a corresponding transmission wheel on the jet tube within the carriage body in mesh with the first-mentioned transmission Wheel for rotating the jet tube.

5. A soot removing apparatus for heat transmission systems, comprising, in combination, a frame beam having a cross-section in the form of an inverted U, a jet tube mounted for longitudinal and rotary movement in said frame beam, a valve for supplying a blowing medium through the jet tube, a carriage mounted within said frame beam for performing a longitudinal movement in parallel with the jet tube and simultaneously with the same, a driving endless chain extending within the frame beam in parallel with the jet tube one flight of said chain being coupled with the carriage for moving the same in the longitudinal direction, and transmission means on said carriage operatively interconnecting the other flight of the chain and the jet tube for imparting a rotary movement to the jet tube.

6. A soot removing apparatus for heat transmission systems, comprising, in combination, a frame, a jet tube mounted for longitudinal and rotary movement in said frame, a main valve for supplying a blowing medium through the jet tube, a servo-valve for controlling the main valve in dependence upon the movement of the jet tube, a carriage mounted in said frame for performing a longitudinal movement in parallel with the jet tube and simultaneously with the same, said servo-valve being provided in a position allowing actuation by the carriage when in a predetermined position of its longitudinal movement, a driving endless chain extending in parallel with the jet tube one flight of said chain being coupled with the carriage for moving the same in the longitudinal direction, an electric motor for driving the chain, transmission means on said carriage operatively interconnecting the other flight of the chain and the jet tube for imparting a rotary movement to the jet tube, and switching means for controlling the electric motor, said switching means being provided in a position allowing actuation by the carriage when in a predetermined position of its longitudinal movement.

7. A soot removing apparatus for heat transmission systems, comprising, in combination, a frame, a jet tube mounted for longitudinal and rotary movement in the frame, a valve for supplying a blowing medium through the jet tube, a nozzzle on jet tube, comprising at least one aperture for emitting the blowing medium, a driving transmission for imparting to the jet tube both a rotary movement and a longitudinal movement between a rear position of rest and a front position of reversal, said two movements being simultaneous with each other over the major part of the same, said aperture moving in a helical path during the rotary and longitudinal movement of the jet tube, and means in said driving transmission for stopping the rotary movement of the jet tube for a predetermined time interval at the front position of reversal, the helical path of said aperture upon reversal thereby being displaced in phase against the helical path of said aperture before reversal.

8. A soot removing apparatus for heat transmission systems, comprising, in combination, a frame, a jet tube mounted for longitudinal and rotary movement in said frame, a valve for supplying a blowing medium through the jet tube, a nozzle on the jet tube, having at least one aperture for emitting the blowing medium, a driving transmission for imparting two combined movements to the jet tube, viz. a rotary movement and a longitudinal movement between a rear position of rest and a front position of reversal, said two movements being simultaneous with each other over the major part of the same, said aperture moving in a helical path during the movement of the jet tube, said driving transmission including a rotatable transmission wheel with a shaft, the direction of notation .of said wheel and shaft being reversable for reversing the movement of the jet tube, said rwhee'l bein-g mounted on its shaft with a lost motion in the direction of rotation :for stopping the rotary movement of the jet tube .for a predetermined time of interval at the front position of reversal for causing a phase displacement of the helical path of said aperture upon reversal relative to the helical path of the same before reversal, the extent of said lost motion in the circumferential direction corresponding .to the value of said phase displacement.

9. A soot removing apparatus for heat transmission systems, comprising, in combination, a frame, a jet tube mounted for longitudinal and rotary movement in said frame, a valve for supplying a blowing medium through the jettube, a nozzzle on the jet tube, having at least one aperture for emitting the blowing medium, a carriage mounted in said frame for performing a longitudinal movement dnparallel :with the jet tube and simultaneously with the same, .a driving endless chain extending in parallel with :the jet tube one flight .of said chain being coupled with the carriage for moving the same in the longitudinal direction between -a :rear position of rest and .a front position of reversal, transmission means on said carriage operatively interconnecting the other flight of thechain and the jet tube for imparting a rotary move- -ment to the jet tube during the longitudinal movement of the same, said aperture of the nozzle moving in a helical path .during the combined rotary and longitudinal movements .of the jet tube, said transmission vmeans including means for stopping one of said-two movementsof the jet :tube for a predetermined time interval .at the front posi- :tion of reversal, the helical path of said aperture upon reversal thereby being displaced in phase against the helical path of said aperture before reversal.

1-0. A soot removing apparatus for heat transmission systems, comprising, in combination, a frame, a jet tube mounted for longitudinal and rotary movement in said frame, a valve for supplying a blowing medium through the \jet :tube, having at least one aperture for emitting the blowing medium, a carriage mounted in said frame for performing a longitudinal movement in parallel with the jet :tube and simultaneously with the same, a reversible .driving endless chain extending in parallel with the jet tube one flight .of said chain being coupled with the carriage for moving the same in the longitudinal direction between a rear position of rest and a front position of reversal, a transversal shaft in said carriage, a chain wheel on said shaft in engagement with the other flight of the ,driving .chain and thereby driving said shaft, a transmission-wheel on said shaft, a corresponding transmission :wheel .on the -jet tube in mesh with the firstmentioned transmission wheel for rotating the jet tube during the longitudinal movement of .the same, the aperture of the nozzle of the jet tube moving in a helical path during the combined rotary and longitudinal movements of the jet tube, said transmission wheel being mounted on said shaft with a lost motion in the direction of rotation for causing a phase vdisplacement of the helical path of said aperture ,upon reversal relative to the helical path of the same before reversal, the extent of said lost motion in the circumferential direction corresponding :to the value of said .phase displacement.

References Cited in the file of this patent 'UNITED STATES PATENTS 1,924,550 Hibner ,et a]. Aug. 29, 1933 2,324,785 Linaker July 20, 1943 2,441,112 Hibner et a1. May 4, 1948 FOREIGN PATENTS 636,052 Great Britain Apr. 19, 1950 

